1. Field
The present invention relates to information processing apparatuses, methods of starting up the information processing apparatuses, and startup programs of the information processing apparatuses. Particularly, the present invention relates to an information processing apparatus capable of being started up from a hibernation state, a method of starting up the information processing apparatus, and a startup program of the information processing apparatus.
2. Description of the Related Art
The power consumption of information processing apparatuses tends to increase as the information processing apparatuses have become sophisticated and faster in recent years. On the other hand, various technologies of reducing the power consumption in the information processing apparatuses are under development with the object of decreasing the calorific value and of energy saving.
Particularly, in portable information processing apparatuses typified by notebook computers, there is a great need for electric power saving because power is supplied from batteries, such as secondary cells, to the portable information processing apparatuses.
In order to satisfy such a need, for example, a method in which the operation of an information processing apparatus is automatically suspended when a user does not operate the information processing apparatus for a predetermined time period and a predetermined device in the information processing apparatus is turned off to reduce power requirements has been adopted hitherto.
In another method of reducing power requirements, an information processing apparatus is set to a suspended state called a standby state. In the standby state, the devices, other than the main memory and the video memory, in the information processing apparatus are turned off.
The main memory and the video memory store information required to return the information processing apparatus to the state immediately before the suspension when the information processing apparatus is resumed from the suspended state. Accordingly, when the information processing apparatus is resumed from the standby state, or the suspended state, by the user who presses an arbitrary key on the keyboard or the power switch, the information processing apparatus can resume the operation from the screen state or operational state immediately before the suspension.
Although the main devices, including the central processing unit (CPU) and the display, are turned off in the standby state, it is necessary to continue to supply power to the main memory and the video memory for maintaining the content of storage.
Consequently, for example, when the information processing apparatus is driven only by the battery, a long standby state exhausts the power in the battery and, as a result, the information processing apparatus eventually loses the content of the main memory and the video memory.
In contrast, there is a method which has a high power saving function and in which the information processing apparatus is set to a dormant state, or a hibernation state.
In the hibernation state, or the dormant state, all the devices in the information processing apparatus are turned off after the state immediately before the halt of the information processing apparatus is stored in a nonvolatile memory, such as the hard disk.
Since there is no need to supply power to the main memory and the video memory in the hibernation state, the power consumption is none in principle (a weak power is supplied to some parts, such as a built-in clock function). Hence, it is possible to halt the information processing apparatus for a long time and, therefore, the hibernation state is particularly advantageous for the operation of the information processing apparatus using the battery as the power supply.
In order to shift the information processing apparatus to the hibernation state, it is necessary to control storage of information required to resume the operation in a predetermined area in the hard disk in a predetermined procedure. In order to resume the information processing apparatus from the hibernation state, it is necessary to control return of the information stored in the predetermined area in the hard disk to the main memory and the video memory.
The control relating to the shift to and resume from the hibernation state (hereinafter referred to as hibernation control) is performed by basic software called a basic input/output system (BIOS), stored in a read only memory (ROM), or by an operating system (hereinafter referred to as the OS).
Although the BIOS has played a leading role in the hibernation control, the hibernation control is shifting from the BIOS-driven control to the OS-driven control with the object of easily addressing the diversity of devices connected to the information processing apparatus in recent years (for example, Jpn Pat. Publication No. 2002-324012).
As described above, the hibernation control can reduce the power consumption of the information processing apparatus in the halt state to zero in principle. In addition, the information processing apparatus can resume the operational state immediately before the halt of the information processing apparatus in resuming from the hibernation state.
In the OS-driven hibernation control, the OS can issue instructions to drivers to store and restore the states of various external devices as long as the drivers of the various external devices (including a card compliant with a peripheral component interconnect (PCI) standard, such as an audio card) connected to the information processing apparatus support the function of the hibernation control.
Since the BIOS must have the control function separately supporting the connected external devices in known BIOS-driven hibernation control, it is difficult to perform the hibernation control for an external device newly added unless the software in the BIOS is changed.
The OS-driven hibernation control can resolve the above problem.
In the OS-driven hibernation control, after a shift request to the hibernation is submitted, the OS stores a variety of information required to resume from the hibernation state in the hard disk and, then, issues a power off instruction. The power supply to each device in the information processing apparatus is stopped in response to the power off instruction to shift the information processing apparatus to the hibernation state.
In the return from the hibernation state, the BIOS is started up in the same manner as in normal startup. After the BIOS performs predetermined processes, the OS is started up.
After the OS is started up, the OS restores the variety of information for the return, stored in the predetermined area in the hard disk, to various devices, including the main memory and the video memory, to resume the information processing apparatus to the state immediately before the hibernation.
In known methods, the same process as in the normal startup is performed in the return from the hibernation state by the BIOS.
Accordingly, in the known OS-driven hibernation control, the same BIOS software can be used in the normal startup and in the return from the hibernation state.
However, the normal startup process performed by the BIOS also includes processes that are not indispensable for the return for the hibernation state and, therefore, there is room for improvement in the known OS-driven hibernation control in terms of the time required for the return from the hibernation state.
In addition, the normal startup process performed by the BIOS includes a setup process in which the user changes the parameters of the devices connected to the information processing apparatus.
It is important to reliably return to the operational state immediately before the hibernation in the hibernation and return control. Accordingly, there is also room for improvement in the known methods, which allows the user to change the parameters of the devices in the return control from the hibernation state, in terms of the reliability of the process.